SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86ff822ffd541cb6ca6dffda35571bebfe1c3330b25ebcedcf86f4299cdb1a79' 
  AND token = 'j22IAJOIGqtnYih4yLKw2B+6ry/vsKAJAQD5VF/y7go=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}